With 109bhp per litre, the F355 engine had the highest specific output per litre of all normally aspirated production cars when it was first manufactured. With a full 8,500 revs available it's a hoot. Service it regularly and it will deliver with surprising reliability. Here's what to watch out for...

Rattling Bypass Valve


The F355 has a system for controlling the exhaust output through the use of something known as a bypass valve. The bypass valve opens up at higher RPM, allowing the exhaust gases to take a more direct route to the tail pipes, thus increasing power and noise.


This means your 355 is quiet around town but when you open it up it screams somewhat. The benefits of the bypass valve are less if you have an aftermarket exhaust fitted, because even the low RPM sounds with the valve closed will be louder.


Over time, the bypass valves seem to wear and eventually they begin to rattle when the car is idling. There are a few solutions to this:

  • Put up with it, and do nothing. This is by far the cheapest solution!
  • Replace the valve with a new one. The new one will wear again, and they cost about £750.
  • Replace the valve with a straight tube (i.e. no bypass). This increases noise at idle.
  • Wire the valve open. If you wrap some strong wire around the valve to hold it in the open position, you will stop the rattle but increase idle noise levels.
  • You may be able to find a manufacturer that does an aftermarket bypass valve.
Cracked Manifolds
This is a very common issue and every car will suffer from it eventually. The problem lies in the design of the manifold. When constructed, the tubing is bent to the point that it becomes relatively thin, and with the manifolds running at a very high temperature the metal eventually cracks. This results in a ticking sound at idle and if you put your hand inside the engine bay you may even be able to feel the air compressions that result from the leak.
This problem can be sorted in three ways:

  • You can get a new manifold from Ferrari. I would not recommend this option because this is a design fault and Ferrari have not redesigned the part. Therefore it will fail again and with manifolds being around £1000 per side this is not cost effective. Ferrari have been known to replace manifolds under warranty but with the cars aging only the very latest cars at the time of writing are still under warranty.
  • You can buy an aftermarket manifold. TUBI do one, but it is very expensive at around £4000 for the pair. There are claims of increased power from these (they are actually for racing) but realistically they probably aren't worth the money. NA Performance are another company that have recently produced a replacement manifold which is a lot cheaper than the TUBI ones.
  • You can get your existing manifolds reconditioned. A UK company called QV London will do this for you at around £500 per side. They remove the cracked tubing and replace it with a piece of thicker gauge. To date no-one has had a failure from a reconditioned manifold.
Removal of the manifolds can be a reasonable job or a fairly big job, depending upon the side that has failed. Looking from the rear of the engine, at the right side there is an oil tank (the car is dry sump) which must first be removed before the right manifold can be removed. This adds a few hours to the job. The left side can be removed more easily. The right side will go first - I speak from experience!
Electronic Suspension
The electronic suspension has two settings - sport and comfort mode - and these are controlled by the use of electronic shock absorbers. At the top of each shocker is an actuator that controls the stiffness of the shocker. These have been known to fail and can be relatively easily replaced. If there is a problem with the electronic suspension, there is a warning lamp that will light up on the dashboard. It will come on at ignition time but should go out shortly afterwards under normal operation.
Heater Valve
You know how it is - you use your car with the aircon on all summer, and then when it comes to winter time you switch on the heat only to find that it doesn't work. The heating system operates via an electronic valve that moves to allow hot water through the heater matrix acrosss which air is blown to warm it up. There are a couple of possible reasons for failure - either the aircon ECU has failed, which controls the position of the heater valve, or the motor on the heater valve itself has failed. The heater valve unit, which includes motor, gearbox, and valve, is about £175 to replace plus around an hour for labour (if that). There are problably other possibilities for failure, but these two are the most common. ECUs are a lot more expensive than the valve.
Engine Bay Fires
Don't let this one frighten you, but it needs to be included as it has happened. I know of two cars that have suffered from engine bay fires. The cause is unknown but there are a couple of recalls that were made by Ferrari that relate to possible fires. These can be found here: http://www.theaa.com/allaboutcars/recalls/index.jsp?makeName=Ferrari&makeId=B2. One of these relates to the fuel line retaining nuts, which if overtightened can crack and this results in a fuel leak. Another problem is that a water hose retaining clamp, incorrectly positioned, can chafe against a fuel line and cause a leak.
One of the engine bay fires was put down to an electrical problem by the insurance loss adjuster, but this is unconfirmed.
You can check whether recall work has been done by communicating with Ferrari; supply the chassis number of the vehicle.
Catalytic Converters
Catalytic converters are of the ceramic type, and will eventually fail. They will either gradually break down and blow out of the exhaust pipe, or simply degrade to the point of being ineffective. The end result will be that your car will fail an emmissions check. There are a few solutions to this one;

  • Buy replacement cats from Ferrari. Probably not the best option.
  • Buy replacement aftermarket cats. Hyper-flow cats are a common one to use.
  • You can have your existing cats restuffed by a specialist (not a taxidermist!)
  • You can lose the cats altogether and replace them with bypass pipes. This is the option many people go for but it does of course depend upon emmission regulations in your area. This option is usually linked to installation of an aftermarket exhaust.
Sticky Throttle Pedal
Most cars suffer from a problem whereby the throttle seems to resist your foot pressure at the top of the pedal travel. This tends to make it a little tricky to drive slowly in traffic until you get used to it. The early cars had a slightly different throttle mechanism and these can be upgraded with the newer parts (there is a quadrant on the throttle cable that was updated). However the problem was never fully corrected by Ferrari, so most specialists when they service the vehicle lubricate the throttle to help with the issue. After lubrication the behavior is always improved but it doesn't usually last until the next service. One of those things you just get used to.
Valve Guides
This is the big one. The valve guide issue has been much discussed on web forums such as www.ferrarichat.com, and there are a lot of horror stories to read about it. The truth is that if it happens it is very expensive, but only a small percentage of cars have actually experienced the problem and most of those did so fairly early in their life. There is no guarantee but a later car (say, 97 or 98 onwards) is much less likely to experience the fault.
The first cars built used bronze valve guides, and these very soft guides tend to wear too easily. Once worn the guides allow oil to leak past them and this results in the engine burning oil. Left unchecked, the oil will eventually run low resulting in signficant engine damage. The results of a compression test (which you should be getting as part of a pre-purchase inspection) can give you an indication as to the condition of the engine in this respect.
Later cars had their valve guides changed to steel. It is not possible to tell which guides your car has just by looking at the build year or registration number, because Ferrari seemed to use both materials for a while. To find out, get the car's chassis and engine number, and query Ferrari either through a dealer or directly.
Engine rebuilds can be around £7000 to correct this problem, so it does warrant very careful checking. You should keep the results of your pre-purchase inspection and then have a compression check say every couple of years to compare. This will help you understand how your engine is wearing.


Here is an interesting write-up on the valve guides issue from FerrariChat.